High-frequency current conductor



y 28, 1953 J. w. DE RUITER 3,091,655

HIGH-FREQUENCY CURRENT CONDUCTOR Filed June 29. 1960 INVENTOR JACOB WILLEM DE RUITER Lava/ p-% AG NT limited rates @atent 3,091,655 HlGH-FREQUENCY CURRENT QONDUQTQR Jacob Willem De Ruiter, Eindlioven, Netherlands, assignor to North American Philips Company, Inc New York, N.Y., a corporation of Delaware Filed June 29, 1960, Ser. No. 39,595 Claims priority, application Netherlands .luiy 3, 1959 2 Claims. (Cl. 17432) The invention relates to a conductor for high-frequency currents for inductive high-frequency heating, this conductor consisting in known manner of thin, relatively insulated metal strips.

For conducting high currents (for example about 1000 A.) with very high frequencies, in general in the case of low-ohmic generators, it is advisable to use two or more parallel-connected conductor pairs (Lecher con ductors), since the width of each conductor in itself would otherwise become unpractically large and the thickness is subjected to a given maximum with a view to a certain degree of desirable flexibility.

However, if a plurality of conductor pairs are piled up, difficulties arise with the connection at the two ends, where the double requirement of a low inductance and a uniform current distribution across the width of the conductors is to be fulfilled.

The invention has for its object to provide such a construction of a conductor consisting of thin, relatively insulated metal strips that can be readily connected at the two ends, which the aforesaid double requirement is fulfilled.

In accordance with the invention the strips of the conductor are T-shaped and alternately stacked so that the stnaight ends of one half projects beyond the transverse yokes of the other half, where they are conductively connected to each other having been bent over at right angles, whereas the ends of the transverse yokes, after having been bent over also at right angles, are conduc tively connected to each other and to a bracket, which is provided with a central tag, bent over at the end, the arrangement being such that at each of the two ends of the conductor there are two approximately co-planar tags, suitable for connecting purposes and bent over in opposite directions.

The accompanying drawing shows one embodiment of a conductor according to the invention consisting of four strips.

The strips 1, 2, 3 and 4 are identical T-shaped strips, cut from sheet metal, for example, copper of a thickness of 0.3 mm. These strips are stacked up with the interposition of layers of insulating material (not shown), for example Teflon, a temperature-resistant synthetic substance, which has suitable properties for high-frequency insulation constituted of a tetrafluoroethylene polymer manufactured by the E. I. du Pont de Nemours Co. of Wilmington, Delaware.

The strips 1 and 3 are arranged with their transverse yokes 5 and 6 respectively to the right and the two strips 2 and 4 with their transverse yokes 7 and 8 respec tively to the left so that the limbs of the strips project slightly beyond the adjacent transverse yokes.

The ends of the yokes are bent over at right angles, the yokes 5 and 6 upwardly and the yokes 7 and 8 downwardly. The bent-over parts engage each other pairwise in flat positions and are conductively connected pairwise with each other and with metal bridges 9 and 10 respectively, for example, by soldering. To this end these bridges are provided with bent-over ends, which grasp around the bent-over ends of the transverse yokes,

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which they engage in flat positions. The bridges are furthermore provided with tags or flanges 11 and 12 respectively, which are bent over at the ends at right angles and which serve to connect two of the terminals of the conductor. The connecting bridges may be cooled by water.

The tag-shaped ends of the strips projecting beyond the transverse yokes are bent over in opposite directions: those of the strips 1 and 3 upwardly and those of the strips 2 and 4 downwardly. This is carried out so that they engage each other pairwise in flat positions, approximately in the plane of the bent-over parts of the flanges 11 and 12 of the bridges. They are then conductively connected to each other, for example, by soldering and may serve for connecting the two further poles of the conductor.

*In the embodiment :shown and described above the number of strips of which the conductor consists is chosen to be small in order to give a clear survey of the drawing. However, the number of strips may be chosen arbitrarily high, within certain limits. Satisfactory results have been obtained, for example, by means of a conductor consisting of twelve strips, each having a length of 1 meter, a width of mms. and a thickness of 0 .3 mm.

What is claimed is:

l. A high frequency current conductor assembly comprising a plurality of spaced, relatively insulated metal strips, each of said strips being T'-shaped at one end and having end portions depending therefrom at right angles to the longitudinal axis of said strip, said other end of said T-shaped strip having a flange thereon extending perpendicular to the longitudinal axis of said strip but in a transverse plane to the plane of said end portions, said strips being stacked in an alternate relationship whereby the other end of each of said strips is juxtaposed to said T-shaped end of the adjacent strip and projects laterally beyond said T-shaped end, and a bracket located at each end of said current conductor assembly, said end portions being conductively connected to each other and to said bracket, said brackets each having mounting flanges extending substantially co-planar to the flanges on the other end of said T-shaped strips and substantially perpendicular to the longitudinal axes of said metal strips.

2. A high frequency current conductor assembly comprising a plurality of thin, spaced, relatively insulated metal conducting strips, each of said strips being T-shaped at one end and having end portions depending therefrom at right angle to the longitudinal axis as said strip, said other end of said T-shaped strip having a flange thereon extending perpendicular to the longitudinal axis of said strip but in a plane transverse to the plane of said end portions, said strips being stacked in an alternate, superposed relationship whereby the other end of each of said strips is juxtaposed to said T-shaped end of the adjacent strip and projects laterally beyond said T-shaped end, and a bracket located at each end of said current conductor assembly, said end portions being in a flat and conducting engagement with each other and said bracket, said brackets each having mounting flanges extending substantially co-planar to the flanges on the other end of said T-shaped strips adjacent thereto and substantially perpendicular to the longitudinal axes of said metal strips.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A HIGH FREQUENCY CURRENT CONDUCTOR ASSEMBLY COMPRISING A PLURALITY OF SPACED, RELATIVELY INSULATED METAL STRIPS, EACH OF SAID STRIPS BEING T-SHAPED AT ONE END AND HAVING END PORTIONS DEPENDING THEREFROM AT RIGHT ANGLES TO THE LONGITUDINAL AXIS OF SAID STRIP, SAID OTHER END OF SAID T-SHAPED STRIP HAVING A FLANGE THEREON EXTENDING PERPENDICULAR TO THE LONGITUDINAL AXIS OF SAID END PORTIONS IN A TRANSVERSE PLANE TO THE PLANE OF SAID END PORTIONS SAID STRIPS BEING STACKED IN AN ALTERNATE RELATIONSHIP WHEREBY THE OTHER END OF EACH OF SAID STRIPS IS JUXTAPOSED TO SAID T-SHAPED END OF THE ADJACENT STRIP AND PROJECTS LATERALLY BEYOND SAID T-SHAPED END, AND A BRACKET LOCATED AT EACH END OF SAID CURRENT CONDUCTOR ASSEMBLY, SAID END PORTIONS BEING CONDUCTIVELY CONNECTED TO EACH OTHER AND TO SAID BRACKET, SAID BRACKETS EACH HAVING MOUNTING FLANGES EXTENDING SUBSTANTIALLY CO-PLANAR TO THE FLANGES ON THE OTHER END OF SAID T-SHAPED STRIPS AND SUBSTANTIALLY PERPENDICULAR TO THE LONGITUDINAL AXES OF SAID METAL STRIPS. 